You will write a paper of several paragraphs describing your model and the conclusions drawn from the group
activity.
Background Information
The cycle of seasons is caused by Earth's tilt toward the Sun. Earth makes a complete orbit around the
Sun every 365.25 days. It spins on an invisible axis that is tilted at an angle of 23.5°. The angle does not
change; only the direction of the axis in relation to the Sun changes.
The north end of the axis points away from the Sun for half of year and toward the Sun for the other half.
Depending on the time of year, some parts of Earth are tilted more toward the direct rays of the Sun than
other parts. Parts of Earth that get more direct rays get warmer, and parts that get fewer direct rays are
cooler. The difference in the amount of heat and light available at Earth’s surface determines the
seasons.
Seasons vary from one part of the world to another. At different times during the year, the Northern or
Southern Hemisphere is closer to the Sun. When it is summer in the Northern Hemisphere, it is winter in
the Southern Hemisphere. When it is winter in the Northern Hemisphere, it is summer in the Southern
Hemisphere. Both hemispheres get similar amounts of energy from the Sun during fall and spring.
Materials